Q. There were two things that particularly intrigued me about this piece. One is that you wrote the paper during a time of dramatic change in same-sex marriage laws both at the state and federal level. The US Supreme Court struck down part of the federal Defense of Marriage Act in United States v. Windsorwhile you were writing the paper, and they gave same-sex couples the right to marry in Obergefell v. Hodges a few months after the paper was published. This piece offers insight on why things unfolded the way they did. The other, of course, is that you wrote the paper with your dad. Tell me a bit about the project and how your interests came together.
A. It was the first paper my dad and I wrote together, and it was an exceptional experience. He’s a retired law professor, but he’s still working. He has been writing a book about the influence of the American constitution on the drafting and interpretation of the Australian constitution, which followed ours by roughly 100 years. In teaching a seminar on comparative family law a few years back, I discovered that there was a family law piece to that story of influence. Although the Australian framers were generally interested in replicating our federalism design—a lot of power left to the states, only enumerated powers given to the federal government—they were horrified by what was going on with divorce law in the United States at the time of their constitutional drafting. Different American states had different divorce laws, which meant that people could move from one state to another and get divorced, and then move back and have their marital status questioned. The Australians didn’t want what they saw in America, so they included control over marriage and divorce as an enumerated national power—a definite and intentional departure from the American model.

We decided to write a paper that told the story of that divergence, and then considered its impact on the development of divorce law, and, then, on the development of the law surrounding same-sex marriage. These are two of the biggest changes in family law that reflect societal shifts. Divorce was the obvious starting point—two countries were trying to solve the same problem and understood that their federalism design would make a difference. With same-sex marriage, each country was locked into a set of federalism rules that impacted how they dealt with the issue.

Q. So the Australians were so scandalized by the lack of uniformity in our divorce laws—this “blot” on the United States Constitution—that they were willing to make marriage and divorce a national issue, even though they had modeled their constitution on ours largely because they admired the amount of power we left to the states?
A. Yes—and, by the way, what they were seeing scandalized a lot of Americans, too. The way divorce law was playing out in the United States created a lot of instability and uncertainty, and it really raised the question of what should be done when states have very different ideas about an important moral issue. So the Australians enumerated a power to their national parliament to regulate marriage and divorce—although the parliament didn’t do anything with its power for a long while. They sat on it, in large part because, in Australia as in the United States, there were sharp differences in views about divorce. The punch line, of course, is that both countries ended up in very much the same place; America just did it state by state and Australia through national legislation

Q. We just took different paths to the same destination?
A. Right. But I think you can argue that the path mattered. In America, we had all this state diversity and a lot of years of struggle trying to figure out whether states had to recognize divorces from other states. Ultimately, we applied our Full Faith and Credit doctrine to require states to recognize divorces decreed in other states, which was our solution in the divorce context. That, over time and with other trends and changes in society, probably led to an increasing interest throughout the country in the same end, which was no-fault divorce. In Australia, they had some amount of diversity, but they had to wait until there was a national consensus—and then whole-hog across the nation, they had no-fault divorce.

Q. In the paper, you argue that there were upsides to America’s lack of uniformity, particularly the ability to experiment at the state level. Has Australia suffered from this lack of state-level experimentation with same-sex marriage laws?
A. At this stage, they’ve boxed themselves in. With divorce, there was this period where they had the opportunity to experiment at the state level because they didn’t yet have national law. With marriage, Australia’s parliament exercised is national power and enacted a law that limited marriage to unions between opposite sex couples. This prevented states from defining marriage to include same sex couples— even though there is growing interest in some states in doing so. The issues are too complex to say “but for …” but it seems quite plausible that some states in Australia would have legalized same-sex marriage if they didn’t have this national constraint. And the inability to experiment at the state level may have also slowed the development of a national consensus. We saw in the United States how much state-level action on same-sex marriage affected attitudes throughout the nation.

Q. Did America achieve consensus faster because we were able to try things out at the state level?
A. It is way too complicated to know for sure, but it might well have been a factor.

Q. With the Court’s Obergefell ruling in June, we have a national consensus—or at least a national rule—in America on same-sex marriage. What impact might this have on our federalism design when it comes to family law? Are we moving from state-level control to national regulation?
A. We can’t say what will happen, and the outcome in Obergefell was clearly driven by the justice’s view about the specific question before them, but people who are concerned about a national judicial takeover could legitimately say that this decision, and particularly the kind of language employed by [US Supreme Court Justice Anthony] Kennedy for the majority, is boundless. Not only could family law generally shift in the direction of national judge-made law, but it could inspire far-reaching challenges to the limits to personal liberty imposed by our family law. The Obergefell decision opens the door for a broader concept of constitutional protection for individual liberty in family formation and functioning.

Q. What can we learn from Australia’s path?
A. The negative is that they boxed themselves in. The positive: there is a lot to be said for a commitment to not making major shifts in law that affect social policy and are grounded on your society’s moral values without having a broad consensus across your country.

Q. What do you hope readers take from this paper?
A. An appreciation for the complexity of cause and effect between legal structure and outcomes. You can draw rough causal connections but then have to recognize that there are other factors playing a role. The framers predicted some things, but didn’t predict other things. The Australians were very purposeful—they identified a particular thing they wanted to avoid, and they figured out how they wanted to avoid it. But in the end they didn’t totally avoid it, and even to the extent they succeeded, they created other problems they may not have anticipated. They thought the only thing they needed to worry about was divorce—but who knew that 100 years later they would have a whole different question to answer? It is hard to develop a legal structure that is best equipped to deal with unforeseen future legal and social developments.

Q. What was it like writing a paper with your dad?
A. It was fantastic—I have always admired him as a teacher and a scholar, but this opportunity to work together, to mix it up the way any successful co-authors should do, was a real gift. I learned a huge amount from him, about federalism and the Australian Constitution, to be sure, but also about the craft. I was always more ready than he was to reach the big bold conclusion. His breadth of knowledge and patience as a scholar pushed us both to a more subtle understanding of our story.